curvature versus slope
  n = 109118 
  X=0, Y = 42.68 +/- 24.38 
  Weighted least-squares fit:  Y = 62.5 + 1.707 X  + -0.01848 X**2 

slope versus dZ, curvature < 5
  n = 16514 

  Weighted least-squares fit:  Y = 61.3 + -1.461 X  + 0.01430 X**2 
     at X = 100, Y = 58.2 
     Bad fit. P2 = 0
slope versus dZ, curvature < 15
  n = 31353 

  Weighted least-squares fit:  Y = 62.1 + -1.455 X  + 0.01532 X**2 

curvature versus dZ, slope < 10
  n = 2452 
  X=0, Y = 49.46 +/- 14.01 
  Weighted least-squares fit:  Y = 49.9 + -0.254 X  + 0.16074 X**2 


Number of samples 110197
Max dz = 900
Mean dz = 86
RMS dz = 135.09996299
100cm = 70.9139087271 percentile value of dz